Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Depreciation / property basis	$ (531.5)		$ (517.0)
Income taxes recoverable	(11.4)		(12.3)
Regulatory assets	(15.6)		(20.6)
Investment tax credit	1.0		1.2
Intangibles	(3.9)		(2.4)
Compensation and employee benefits	(2.0)		2.2
Long-term debt	(1.7)		(2.0)
Other	0.8	[1]	16.0	[1]
Net noncurrent (liabilities)	(564.3)		(534.9)
Other	(2.6)		4.7
Net current assets	(2.6)		4.7
Deferred tax assets related to state and local tax net operating loss carryforwards, net of related valuation allowances			20.4
DP&L [Member]
Depreciation / property basis	(607.1)		(622.1)
Income taxes recoverable	(11.4)		(12.3)
Regulatory assets	(15.6)		(20.6)
Investment tax credit	8.8		9.6
Compensation and employee benefits	(0.2)		0.3
Other	(6.8)		(6.9)
Net noncurrent (liabilities)	(632.3)		(652.0)
Other	(5.0)		2.0
Net current assets	$ (5.0)		$ 2.0

[1] (c)The Other non-current liabilities caption includes deferred tax assets of $20.7 million in 2013 and $20.4 million in 2012 related to state and local tax net operating loss carryforwards, net of related valuation allowances of $16.6 million in 2013 and $16.2 million in 2012. These net operating loss carryforwards expire from 2014 to 2027.